Mixtures of 2,4- and 2,6-lower alkyl cyclohexylenediamines



United States Patent ABSTRACT OF THE DISCLOSURE Mixtures of isomers oflower alkyl cyclohexylene diamines.

This application is a division of parent application, Ser. No. 371,842,filed June 1, 1964, now U. S. Patent No. 3,351,650, issued Nov. 7, 1967,which in turn was a continuation-in-part of Ser. No. 326,243, filed Nov.26, 1963, now abandoned.

This invention relates to organic polyamines, organic polyisocyanatesand polyurethane plastics prepared there from. More particularly, thisinvention relates to substituted cyclohexylene polyamines,polyisocyanates and improved light-stable polyurethanes based onsubstituted cyclohexylene polyisocyanates. This application is acontinuation-in-part of our copending application Ser. No. 326,243.

The compound 2,4-hexahydrotoluene diisocyanate is disclosed in Annalender Chernie, 532, 125 (1948). This compound in pure form has not becomecommercially important in spite of many apparent advantages for using itin the preparation of light-stable polyurethane plastics.

It is therefore an object of this invention to provide desirablesubstituted cyclohexylene polyamines, substituted cyclohexylenepolyisocyanates and light-stable polyurethane plastics preparedtherefrom. Still another object of this invention is to providecyclohexylene based diamines and diisocyanates which will react smoothlyand evenly with active hydrogen containing compounds to produce improvedpolyurethane plastics. Still a further object of this invention is toprovide cyclohexylene based diisocyanates which exhibit improvedproperties and are easier to prepare than heretofore known cyclohexylenepolyisocyanates. Still another object of this invention is to provide amethod of preparing substituted cyclohexylene diisocyanates. Stillanother object of this invention is to provide casting compositions,elastomers and cellular polyurethane plastics based on these mixedisomers of cyclohexylene based polyisocyanates.

The foregoing objects and others which will become apparent from thefollowing description are accomplished in accordance with the invention,generally speaking, by providing lower alkyl cyclohexylene polyaminesand polyisocyanates and polyurethanes prepared therefrom.

Thus, this invention contemplates mixed isomers of lower alkylcyclohexylene diamines, the lower alkyl cyclohexylene polyisocyanatesprepared therefrom and in turn polyurethanes prepared from thesepolyisocyanates. The diamines of the invention are mixtures which may bephosgenated to prepare mixtures of isocyanates which have littletendency to settle out of solution and thus are more compatiblewithorganic compounds. This property makes the mixture of the isocyanatesparticularly useful for the preparation of polyurethane plasticsparticularly coatings, foams and elastomers. The mixtures of isocyanatesof this invention have less tendency to dimerize than the heretoforeknown pure compound, 2,4-hexahy- 3,419,612 Patented Dec. 31, 1968drotoluene diisocyanate. The storage stability of the mixtures ofisocyanates of this invention is better than the storage stability ofthe pure compound with less tendency toward sediment and solids whichare troublesome in polyurethane plastic preparation. Consequently thesenew isocyanates offer the advantage of simultaneous improved chemicalcompatibility with the other components in a polyurethane plasticformulation and improved physical compatibility because of less solidswhich tend to feed plug lines and small orifices in machine mixingequipment.

No attempt is made herein to explain the improved compatibility of themixed isomers with organic components of polyurethane coatings or foams.It is pointed out, for example, that a mixture of 2,4- and2,6-hexahydrotoluene diisocyanate has a lower melting point than thepure 2,4-isomer and that it is believed that the 4 position reacts morerapidly than the others with active hydrogen compounds.

The mixture of isomers is preferably such that there is at least 50percent of the 2,4-isomer present and at least 5 percent of the2,6-isomer present. Particularly preferred compounds are mixtures of 65percent 2,4- and 35 percent 2,6-hexahydrotoluene diamine or diisocyanateas the case may be and percent 2,4 and 20 percent 2,6-hexahydrotoluenediamine or diisocyanate.

The isocyanates of the present invention are preferably prepared in atwo-step process. In the first. stage, the corresponding aromaticamines, for example, 2,4- and 2,6- toluylene diamine, are hydrogenatedto prepare the amines of the invention such as hexahydrotoluene2,4-diarnine and 2,6-diamine. In the second stage, the amine is converted to the isocyanate, preferably by reaction with phos' gene. In thehydrogenation stage, any suitable hydrogenation catalyst is usedpreferably together with a solvent and the reaction is preferablycarried out under pressure and by any suitable hydrogenation reactionincluding those disclosed in Us. Patent 2,817,444. Any suitablehydrogenation catalyst may be used including, for example, platinum,ruthenium, rhodium, nickel, copper, chromium alloys, base promotedcobalt catalysts such as disclosed in OPB Report PB-742 (1941), and thelike. Depending on the selection of the hydrogenation catalysts, thetemperature of hydrogenation may vary over a wide range, preferablybetween about 25 and about 300 C. and most preferably in the range ofabout 50 to 250 C. The hydrogenation can be carried out in the presenceof ammonia to reduce side reactions. Moreover, the hydrogenationreaction may be carried out at atmospheric pressure or even at elevatedpressures of up to about 5,000 p.s.i.g. The most preferred hydrogenationpressure is from about 50 p.s.i.g. up to about 1500 p.s.i.g.

In the event that percent conversion of the aromatic amine to thecycloaliphatic compound is not obtained, then it is possible to separatethe saturated ring amines from the aromatic amines by distillation sincethe toluylene diamine boils at about 280 to 284 C. and thehexahydrotoluene diamine boils at about 207 C.

The resulting amines could be represented by the formula:

CHR

C H\ CH C H (N 11:)2

wherein R is lower alkyl such as methyl, ethyl, propyl, butyl and thelike with the proviso that there are at least two separate isomerspresent in the product. Preferred examples are mixtures of 2,4- and2,6-lower alkyl cyclohexylene diamine. The mixed isomers of amines giveimproved solubility in solvents, thus facilitating conversion to thecorresponding isocyanate. Illustrative specific examples of aminescontemplated are mixtures of 2,4hexahydrotoluene diamine with2,6-hexahydrotoluene diamine, mixtures of ethylcyclohexylene-2,4-diamine with ethyl cyclohexylene 2,6 diamine, andcorresponding propyl and butyl derivatives, and the like, includingmixtures of ethyl cyclohexylene-2,4-diamine with 2,6-hexahydrotoluenediamine and the like. It is preferred to have at least 50 percent of themixed isomers present as the 2,4-isomer and at least 5 percent as the2,6-isomer because these offer improved compatibility with solvents thusfacilitating conversion of the amine to the isocyanate.

In the conversion of the cycloaliphatic amine to an isocyanate, anysuitable known process may be used including, for example, phosgenationof the amine or an amine salt as, for example, disclosed at p. 108 ofthe Annalen der Chemie article supra. It is preferred to use theso-called cold phase-hot phase phosgenation process wherein the amine ismixed with an inert organic solvent such as, for example,monochlorobenzene, dichlorobenzene, toluene and diethyl ether ofdiethylene glycol or the like and then combined with CO to form a saltand the salt is mixed with phosgene at a temperature preferably betweenabout C. and about 80 C. in a first step to produce a mixture ofcarbamyl chloride and amine hydrochloride which forms a slurry. Theslurry is then further phosgenated at a temperature of from about 50 C.to about 200 C. to prepare the isocyanate.

Preferred isocyanates of the invention may be represented by theformula:

CH (NCO)Z wherein R is a lower alkyl radical such as methyl, ethyl,propyl, butyl and the like with the proviso that there are at least twoisomers present in the product of which preferably at least 50 percentare 2,4-isocyanato isomers and at least 5 percent are 2,6-isocyanatoisomers.

Illustrative mixtures of isocyanates contemplated by the presentinvention include mixtures of lower alkyl cyclohexylene diisocyanateswhich have improved compatibility with polyurethane components such asmixtures of 50 percent 2,4-lower alkyl cyclohexylene diisocyanate withfrom 5 to 50 percent 2,6-lower alkyl cyclohexylene diisocyanate. Apreferred composition of the invention is a mixture of from about 65 toabout 80 percent 2,4- hexahydrotoluene diisocyanate with a correspondingamount to yield a total of about 100 percent within the range of fromabout to about percent of 2,6-hexahydrotoluene diisocyanate. The ethylderivatives may also be used such as, for example, 80 percent ethylcyclohexylene-2,4-diisocyanate and 20 percent ethyl cyclohexylene-2,6-diisocyanate; or the propyl derivatives may be used such as, forexample, 80 percent propyl cyclohexylene- 2,4-diisocyanate, and 20percent propyl cyclohexylene- 2,6-diis0cyanate. Moreover, it is possibleto mix the lower alkyl radicals. Thus, one may mix, for example, 75percent 2,4-hexahydrotoluene diisocyanate with 25 percent ethylcyclohexylene-2,6-diisocyanate. All of the mixtures of isocyanates arecontemplated by the invention but it is preferred that there are atleast two isomers or two isomer homologues in the reaction mixturehaving NCO groups attached to different ring carbon atoms.

A particularly preferred form of the invention is the use of thesemixtures of lower alkyl cyclohexylene diisocyanate isomers to preparelight-stable polyurethane Plastics in a smooth and uncomplicatedfashion. One may prepare coatings, cellular polyurethane plastics ornonporous solid elastomeric polyurethane plastics in accordance with theprocess of the present invention. Moreover, it is not necessary to userefined products but they may be used in their unrefined state togetherwith the by-products of either the phosgenation reaction or thehydrogenation reaction. Moreover, it is possible to use them inadmixture with the conventional heretofore known isocyanates since oncethe rate of reactivity is somewhat adjusted with these compositions, itis possible to produce lightstability and a smooth reaction withouttotally replacing the heretofore known aromatic polyisocyanates. It ispreferred that at least 50 percent by weight of the polyisocyanates usedbe the mixed isomers of this invention.

The polyurethane plastics of the invention are prepared by reacting thecyclohexylene diisocyanates with an organic compound containing activehydrogen containing groups as determined by the Zerewitinoff method.Generally speaking, any compound having an active hydrogen atom asdefined above which Will react with an NCO group to yield urethanegroups whereas carboxylic acids yield amine groups and amines yieldureas. The alcoholic group is strongly preferred because it is readilyavailable and yields a stronger urethane linkage than a phenolic typehydroxyl group. Moreover, to prepare polyurethane plastics, it ispreferred to have an organic compound of the type specified above whichcontains a plurality of active hydrogen containing groups and preferablyat least some alcoholic hydroxyl groups. It is to be understood thatwhen the above terminology is used, active hydrogen containing compoundsare contemplated which may contain any of the following types of activehydrogen containing groups, among others, 'OH, NH NH, COOH, SH and thelike. Examples of suitable types of organic compounds containing atleast two active hydrogen containing groups which are reactive with anisocyanate group are hydroxyl polyesters, polyhydric polyalkyleneethers, polyhydric polythioethers, polyacetals, aliphatic polyols,including alkane, alkene and alkyne diols,, triols, tetrols and thelike, aliphatic thiols including alkane, alkene and alkyne thiols havingtwo or more 1SH groups; polyamines including both aromatic, aliphaticand heterocyclic diamines, triamines, tetramines and the like; as wellas mixtures thereof. Of course, compounds which contain two or moredifferent groups within the above-defined classes may also be used inaccordance with the process of the present invention such as, forexample, amino alcohols which contain an amino group and an hydroxylgroup, amino alcohols which contain two amino groups and one bydroxylgroup and the like. Also, compounds may be used which contain one SHgroup and one -OH group or two OH groups and one SH group as well asthose which contain an amino group and a -SH group and the like.

The molecular weight of the organic compound containing at least twoactive hydrogen containing groups may vary over a wide range.Preferably, however, at least one of the organic compounds containing atleast two active hydrogen containing groups which is used in theproduction of the polyurethane plastic has a molecular weight of atleast about 200 and preferably between about 500 and about 5000 with anhydroxyl number within the range of from about 25 to about 800 and acidnumbers, where applicable, below about 5. A satisfactory upper limit forthe molecular weight of the organic compound containing at least twoactive hydrogen containing groups is about 10,000 but this limitationmay vary so long as satisfactory mixing of the organic compoundcontaining at least two active hydrogen containing groups with theorganic polyisocyanate can be obtained. In addition to the highmolecular weight organic compound containing at least two activehydrogen containing groups, it is desirable to use an organic compoundof this type having a molecular weight below about 750 and preferablybelow about 500 aliphatic diols and triols are most preferred for thispurpose.

Any suitable hydroxyl polyester may be used such as are obtained, forexample, from polycarboxylic acids and polyhydric alcohols. Any suitablepolycarboxylic acid may be used such as, for example, oxalic acid,malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,suberic acid, azelaic acid, sebacic acid, brassylic acid, thapsic acid,maleic acid, fumaric acid, glutaconic acid, alphahydromuconic acid,beta-hydromuconic acid, alpha-butylalpha-ethyl-glutaric acid,alpha-beta-diethylsuccinic acid, isophthalic acid, terephthalic acid,hemimellitic acid, trimellitic acid, trimesic acid, melophanic acid,prehnitic acid, pyromellitic acid, benzene-pentacarboxylic acid and thelike. Any suitable polyhydric alcohol may be used such as, for example,ethylene glycol, 1,3-propylene glycol, 1,2-butylene glycol,1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol,1,5-pentane diol, 1,4-pentane diol, 1,3-pentane diol, 1,6-hexane diol,1,7-heptane diol, glycerine, trimethylolpropane, 1,3,6-hexanetriol,triethanolamine, pentaerythritol, sorbitol and the like.

Any suitable polyhydric polyalkylene ether may be used such as, forexample, the condensation product of an alkylene oxide beginning withany suitable initiator. The initiator may be a difunctional compoundincluding water so that the resulting polyether is essentially a chainof repeating alkylene oxy groups as in polyethylene ether glycol,polypropylene polybutylene ether glycol and the like; or the initiatormay be any suitable active hydrogen containing compound which may be amonomer or even a compound having a relatively molecular weightincluding other active hydrogen containing compounds as disclosedherein. It is preferred that the initiator have from 2 to 8 active sitesto which the alkylene oxides may add, including, for example, amines,alcohols and the like. Any suitable alkylene oxide may be used such as,for example, ethylene oxide, propylene oxide, butylene oxide, amyleneoxide, tetrahydrofuran, epihalohydrins such as epichlorohydrin, styreneoxide and the like. Any suitable initiator may be used including, forexample, water, polyhydric alcohols, preferably having 2 to 8 hydroxylgroups, amines, preferably having 2 to 8 replaceable hydrogen atomsbonded to nitrogen atoms. Phosphorous acids may also be used, but thephosphorous compounds are somewhat peculiar in that a different mode ofpreparation may be required, as more particularly set forth below. Theresulting polyhydric polyalkylene ethers with the various bases ofnitrogen, phosporous and the like may have either primary or secondaryhydroxyl groups or mixtures of primary and secondary hydroxyl groups. Itis preferred to use alkylene oxides which contain from 2 to 5 carbonatoms and, generally speaking, it is advantageous to condense from about5 to about 30 mols of alkylene oxide per functional groups of theinitiator. There are many desirable processes for the preparation ofpolyhydric polyalkylene ethers including U.S. Patents 1,922,459,3,009,939 and 3,061,625 or by the process disclosed by Wurtz in 1859 andin Encyclopedia of Chemical Technology, vol. 7, pp. 257 to 262,published by Interscience Publishers, Inc. (1951).

Specific examples of initiators are water, ethylene glycol, propyleneglycol, glycerine, trimethylol propane, pentaerythritol, arbitol,sorbitol, maltose, sucrose, ammonia, diethanolamine, triethanolamine,dipropanolamine, tripropanolamine, diethanolpropanolamine,tributanolamine, 2,4-tolylene diamine, 4,4'-diphenylmethane diamine,p,p',p"-triphenylmethane triamine, ethylene diamine, propylene diamine,propylene triamine, N,N,N',N'- tetrakis-(2-hydroxypropyl) ethylenediamine, diethylene triamine. The phosphorous containing polyols aremore fully described below.

Any suitable polyhydric polythioether may be used such as, for example,the condensation product of thiodiglycol or the reaction product of apolyhydric alcohol such as is disclosed above for the preparation of thehydroxyl polyesters with any other suitable thioetherglycol. Othersuitable polyhydric polythioethers are disclosed in U.S. Patents2,862,972 and 2,900,368.

The hydroxyl polyester may also be a polyester amide such as isobtained, for example, by including some amine or amino alcohol in thereactants for the preparation of the polyesters. Thus, polyester amidesmay be obtained by condensing an amino alcohol such as ethanolamine withthe polycarboxylic acids set forth above or they may be made using thesame components that make up the hydroxyl polyester with only a portionof the components being a diamine such as ethylene diamine and the like.

Any suitable polyacetal may be used, such as, for example, the reactionproduct of formaldehyde or other suitable aldehyde with a polyhydricalcohol such as those disclosed above for use in the preparation of thehydroxyl polyesters.

Any suitable aliphatic polyol may be used such as, for example, alkanediols such as, for example, ethylene glycol, 1,3-propylene glycol,1,2-propylene glycol, L4 butylene glycol, 1,3-butylene glycol,1,5-pentane diol, 1,4- butane diol, 1,3-pentane diol, 1,6-hexane diol,1,7-heptane diol, 2,2-dimethyl-l,3-propane diol, l,8-octane diol and thelike including 1,20-eicosane diol and the like; alkene diols such as,for example, l-butene-1,4-diol, 1,3-butadiene-l,4-diol,2-pentene-l,5-diol, 2-hexene-1,6-diol, 2- heptene-l,7-diol, and thelike; alkene diols such as, for example, 2-butyne-l,4-diol,1,5-l1exadiyne-l,6-diol and the like; alkane triols such as for example,1,3,6-hexanetriol, 1,3,7-heptane triol, 1,4,8-octane triol,1,6,12-dodecane triol and the like; alkene triol such as 1-hexene-1,3,6triol and the like; alkyne triols such as 2-hexyne-l,3,6-triol and thelike; alkyne triols such as 2-hexyne--l,3,6-triol and the like; alkanetetrols such as, for example, 1,2,5,6-hexane tetrol and the like; alkenetetrols such as, for example, 3-heptene-l,2,6,7-tetrol and the like;alkyne tetrols such as, for example, '4-octyne-1,2,7,8-tetrol and thelike.

Any suitable aliphatic thiol including alkane thiols containing two ormore -SH groups may be: used such as, for example, 1,2-ethane dithiol,1,2-propane dithiol, 1,3- propane dithiol, 1,6-hexane dithiol,1,3,6-hexane trithiol and the like; alkene thiols such as, for example,2-butene- 1,4-dithiol and the like; alkyne thiols such as, for example,3-hexyne-1,6-dithiol and the like.

Any suitable polyamine may be used including for example aromaticpolyamines such as, for example, p-amino aniline, 1,5-diaminonaphthalene, 2,4-diamino toluylene, 1,3,5-benzene triamine,1,2,3-benzene triamine, l,4,5,8- naphthalene tetramine and the like;aliphatic polyamines such as, for example, ethylene diamine,1,3-propylene diamine, 1,4-butylene diamine, 1,3-butylene diamine,diethyl triamine, triethylene tetramine, 1,3,6-hexane triamine,1,3,5,7-heptane tetramine and the like; heterocyclic polyamines such as,for example, 2,6-diamino pyridene, 2,4-diamino-2-aminomethyl pyrimidine,2,5-diamino-1,3,4-thiodiazol and the like.

Phosphorous containing compounds are often advantageously used becauseof the flame retarding effect which they impart to the resultingplastics. These compounds often contain 1 or 2 phosphorous atoms as anucleus and then have alkylene oxideside chains bonded to thephosphorous nucleus through either phosphate or phosphite type linkages.The phosphate compounds are advantageously prepared by condensing amixture of phosphorous pentoxide and water with an alkylene oxide asmore particularly set forth above. It is advantageous to use mixtures ofphosphorous pentoxide and water which correspond to about percentphosphorous pentoxide and about 20 percent water. But any amount withinthe range of about 65 percent to percent phosphorous pentoxide and thebalance water may be used and the whole range is contemplated. Thephosphites are advantageously prepared in accordance with the method ofU.S. Patent 3,009,929 Where triphenyl phosphite, for example, is reactedwith a polypropylene ether glycol to prepare a product having amolecular weight of about 500. Other processes are disclosed in thepatent. It is also possible to use polyethers based on phosphorous whichcontain nitrogen atoms in addition to the phosphorous atoms. Thesecompounds may be represented by the general formula:

wherein R is lower alkyl or phenyl, for example, methyl, ethyl, propyl,butyl and the like and the R is alkylene, preferably having from 1 to 4carbon atoms such as methylene, ethylene, 1,2-propylene, 1,4-butyleneand the like. A preferred compound is dioxyethylene-N,N-bis-(2-hydroxyethyl) aminomethyl phosphonate.

Any of the compounds of any of the classes set forth above may besubstituted with halogen such as, for example, chloro, bromo, iodo andthe like; nitro; alkoxy, such as, for example, methoxy, ethoxy,carbomethoxy, carbethoxy and the like; dialkyl amino such as, for example, dimethyl amino, diethyl amino, dipropyl amino, methylethyl aminoand the like; mercapto, carbonyl, thiocarbonyl, phosphoryl, phosphatoand the like.

In the production of the polyurethane foams, in addition to the organicpolyisocyanate, the active hydrogen containing compound and the blowingagent, which may be water, a halohydrocarbon such asdichlorodifluoromethane, trichlorofiuoromethane or the like, an alkanesuch as hexane or the like, it is often advantageous to include othercomponents which aid in making a product having the best physicalproperties. It is particularly desirable to use a catalyst and astabilizer. Any suitable catalyst may be used, but as has been proposedheretofore, it is often desirable to have a mixture of a tin com poundand a tertiary amine catalyst present. Any suitable tin compound may beused including, for example, stannous chloride or an organic tincompound. It is preferred to use the organic tin compounds such as thestannous salts of carboxylic acids including stannous oleate, stannousoctoate, stannous stearate and the like. But one may also usetetravalent tin compounds including for example dibutyl tin dilaurate,dibutyl tin di-2-ethyl hexoate and the like. Any suitable tertiary aminecatalyst may be used and a particularly strong tertiary amine catalystis triethylene diamine. If weaker catalysts are desired one may use forexample, Nmethyl morpholine, N-ethyl morpholine, diethyl ethanolamine,N-coco morpholine l-methyl- 4-dimethylarnino ethyl piperazine,3-methoxy-N-dimethyl propyl amine, N-dimethyl-N'-methyl isopropylpropylene diamine, N,Ndiethyl-3-diethyl amino propyl amine, dimethylbenzyl amine, permethylated diethylene triamine and the like.

It is often advantageous in the production of cellular polyurethaneplastics to include other additives in the reaction mixture such as, forexample, emulsifiers, foam stabilizers, coloring agents, fillers and thelike. It is particularly advantageous to employ an emulsifier such as,for example, sulphonated castor oil and/ or a foam stabilizer such as asilicone oil such as, for example, a polydimethyl siloxane or an alkylsilane polyoxyalkylene block copolymer. The latter type of silicone oilis disclosed in US. Patent 2,834,748. Where polyhydric polyalkyleneethers are included in the reaction mixture to prepare a cellularpolyurethane plastic, it is preferred to emplOy a silicone oil of theabove patent within the scope of the formula:

0(RzSiO) (Onllzn0) R Itsi o(Rzsio).,(C..lI1,,O),1t"

O(RzSlO)i-(Cnl 2n())z wherein R, R and R are alkyl radicals having 1 to4 carbon atoms 2, q and r each have a value of from 4 to 8 and (C H O)is a mixed polyoxyethylene oxypropylene group containing from 15 to 19oxyethylene units and from 11 to 15 oxypropylene units with z equal tofrom about 26 to about 34.

A preferred compound has the formula:

wherein (C H O) is a mixed polyoxyethylene and oxypropylene blockcopolymer containing about 17 oxyethylene units and about 13oxypropylene units. Other suitable stabilizers are disclosed in CanadianPatents 668,478, 668,537 and 670,091. Other suitable compounds maytherefore have the formula where X is an integer and represents thenumber of trifunctional silicone atoms bonded to a single monovalent orpolyvalent hydrocarbon radical R; R is a monovalent hydrocarbon group asdefined above; a is an integer having a value of at least 1 andrepresents the number of polyoxyalkylene chains in the block copolymer;y is an integer having a value of at least 3 and denotes the number ofdifun-ctional siloxane units, n is an integer from 2 to 4 denoting thenumber of carbon atoms in the oxyalkylene groups; and z is an integerhaving a value of at least 5 and denotes the length of the oxyalkylenechain. It will be understood further that such compositions of matterare mixtures of such block copolymers wherein y and z are of differentvalues and that method of determin ing the chain length of thepolysiloxane chains and the polyoxyalkylene chains give values whichrepresent average chain lengths. In the above formula, R representsmonovalent hydrocarbon radicals, such as alkyl, aryl or aralkylradicals, the polyoxyalkylene chain terminates with a hydrogen atom, Ris an alkyl radical or a trihydrocarbonsilyl radical having the formulaR Si- Where R is monovalent hydrocarbon radical and terminates asiloxane chain, and R represents a monovalent or polyvalent hydrocarbonradical, being monovalent when x is 1, divalent when x is 2, trivalentwhen x is 3, tetravalent when x is 4.

One type of block copolymer is represented when x in the above formulais one, and in this instance a branched chain formula may be postulatedas follows:

where p+q+r=y of the above formula and has a minimum value of 3, theother subscripts being the same as in the foregoing formula. In thisinstance all three of the oxyalkylene chains are joined to the end ofpolysiloxane chains of the type (R SiO)-. Specifically, one could use[Me SiO(Me SiO) The polyisocyanates of the invention may also be usedfor the production of coating compositions. In this case, the organiccompound containing active hydrogen containing groups is reacted withthe polyisocyanates of the invention in an inert organic solventtherefor, such as, for example, methyl formamide, the diethyl ether ofdiethylene glycol, benzene, xylene, benzine and the like.

It is also possible to use the polyisocyanates of the invention in thepreparation of elastomeric products which are non-porous for example byreacting an organic compound containing active hydrogen containinggroups with an excess of the polyisocyanate of the invention in a firststep to prepare an isocyanato-terminated prepolymer under anhydrousconditions. This prepolymer is then reacted in a second step with achain extending agent such as, for example, 1,4-butane diol, 1,3-butanediol, the bis-betahydroxy ethyl ether of hydroquinone, water or the likeby mixing the cross-linking agent with the prepolymer and casting theresulting mixture in a mold.

The polyurethane plastics of the invention are useful wherepolyurethanes have been used heretofore. For example, the foams areuseful for cushions and especially rigid foams are useful for both soundand thermal insulation, for example, for walls of buildings. Thecoatings may be used to coat wood or metals such as steel and the like.The elastomers are useful, for the production of tires or for moldeditems such as gear wheels or the like.

The invention is further illustrated by the following examples in whichparts are by Weight unless otherwise specified.

EXAMPLE 1 About 44 parts of a mixture of about 80 percent 2,4- and about20 percent 2,6-toluylene diamine and about 225 parts of ethanol areplaced in a stainless steel stirred autoclave and about parts of 5percent rhodium on A1 0 are added thereto. Hydrogen is then introducedunder pressure and the temperature is controlled between about 50 and150 C. for about 8 hours or until cessation of hydrogen absorption. Thepressure is released and the contents of the autoclave discharged into aglass flask. After removal of the catalyst by filtration the alcohol isremoved by evaporation. The crude alicyclic diamine mixture is used tomake the corresponding diisocyanate as follows:

About 128 parts of the methyl diamino cyclohexanes obtained as describedabove are dissolved in about 1100 parts of odichlorobenzene and withstirring saturated with carbon dioxide at about 9095 C. After saturationwith carbon dioxide is complete as indicated by no further absorption,the resulting saturated solution is stirred approximately 6 hours atabout 90 to 95 C. The mixture is cooled to a temperature below about 0C., and about 360 parts of gaseous phosgene is introduced. During thephosgene addition the temperature is not allowed to rise above about 0C. The solution is gradually heated to about 160 C., and phosgene iscontinuously introduced at this temperature until a clear solutionresults. At this time the excess phosgene is removed by blowing out withnitrogen gas for about 30 minutes. The crude isocyanate is isolated byfractional vacuum distillation.

EXAMPLE 2 About 108 parts of a mixture of about 80 percent 2,4- andabout 20 percent 2,6-toluylene diamine and about 300 parts of dioxaneare placed in a stainless steel stirred autoclave and about 2.5 parts ofruthenium dioxide are added thereto. Hydrogen is then introduced underpressure and the temperature is maintained at about 100 to about 175 C.for about 8 hours. At this time approximately the theoretical amount ofhydrogen has been absorbed.

The contents of the autoclave are then filtered to remove the catalyst.The dioxane is then distilled off at atmospheric pressure and theresidue is distilled under a partial vacuum to give the colorlessalicylic diamine mixture.

The mixture is reacted with phosgene in accordance with the procedure ofExample 1 to yield a mixture of 2,4- and 2,6-hexahydrotoluenediisocyanate.

EXAMPLE 3 About 100 parts of a polyhydric polyalkylene ether prepared bycondensing propylene oxide with glycerine until a polyalkylene ethertriol having an hydroxyl number of about 56 is obtained, are mixed withabout 39 parts of a mixture of 80 percent 2,4- and 20 percent 2,6-hexahydrotoluene diisocyanate and about 3 parts of water, about 0.3 partof stannous octoate, about 0.5 part of 1-methyl-4-dimethyl amino ethylpiperazine and about 1 part of a silicone oil having the formula wherein(C H O) is a mixed polyoxyethylene and oxypropylene block copolymercontaining about 17 oxyethylene units and about 13 oxypropylene units.These components are mixed in a machine mixer as disclosed in US.Reissue Patent 24,514 and discharged into a mold where they assume acreamy appearance and form a polyhurethane foam in a short time. Theresulting foam has a density of about 2 lbs/ftfi.

EXAMPLE 4 A coating composition is prepared by combining about 10 molsof a mixture of 80 percent 2,4- and 20 percent 2,6-hexahydrotoluenediisocyanate with about 2 mols trimethylol propane and about 3 mols of1,4-butylene glycol. The resulting adduct is then reacted with apolyester prepared from adipic acid and diethylene glycol which has anhydroxyl number of about 56 in such a ratio that there are no free -NCOgroups present but only a slight stoichiometric excess is used and insuch proportions that a 50 percent solid solution in ethyl acetate isobtained. The resulting coating composition may be coated onto wood,metal and the like.

EXAMPLE 5 About 100 parts of a polyether tetrol prepared by condensingabout 4.5 mols propylene oxide onto pentaerythritol until an hydroxylnumber of about 560 is reached, is mixed with about parts of a mixtureof 80 percent 2.4- and 20 percent 2,6-hexahydrotoluene diisocyanate,about 1 part of the silicone oil of Example 3, about 30 parts oftrichlorofluoromethane, about 1.5 parts of 1-methyl-4-dimethyl aminoethyl piperazine and about 0.2 part of dibutyl tin dilaurate on amachine mixer as disclosed in U.S. Reissue Patent 24,514 and dischargedinto a mold where it reacts and expands to form a rigid polyurethanefoam.

EXAMPLE 6 About parts of an hydroxyl polyester having a molecular weightof about 2000, an 0H number of about 56 and an acid number of about 1.5,prepared from about 11 mols of ethylene glycol and about 10 mols ofadipic acid are mixed with about 9 parts of 1,4-butane diol and about28.6 parts of a mixture of about 80 percent 2,4- and 20 percent2,6-hexahydrotoluene diisocyanate, the mixed components cast into a moldand permitted to solidify therein.

EXAMPLE 7 About 100 parts of a polypropylene ether glycol having amolecular Weight of about 2000 and an hydroxyl number of about 56 aremixed with about 27.8 parts of a mixture of 80 percent 2,4- and 20ercent 2,6-tolylene diisocyanate and about 12.6 parts of a mixture of 80percent 2,4 and 20 percent 2,6 hexahydrotoluene diamine and cast into amold. The casting time is improved over the use of aromatic amines aschain extenders.

EXAMPLE 8 (a) In a one-liter stainless steel stirred autoclave ischarged about 153.8 grams (about 1.26 mols) of toluene diamine,consisting of about 80 percent 2,4-isomer and 20 percent 2,6-isomer,about 5.0 grams of ruthenium oxide and about 600 ml. of dioxane(distilled from sodium). The autoclave is purged five times withhydrogen by building the pressure to about 200250 p.s.i.g. and bleedingoff. Reduction to the cyclohexane derivative was accomplished in about40 hours at about -140 C. and at hydrogen pressure of about 3390 to 4400p.s.i.g. An infrared spectrum of the crude product after removal ofdioxane shows only a trace of aromatic material present. Fractionaldistillation in vacuo gave 126 g. of methylcyclohexyldiamine, boilingpoint 73.575 C. at 3.0 to 3.1 mm. A 2.1 gram sample of the diamine(soluble in water) requires about 32.6 ml. of 1 N HCl forneutralization. Calculated molecular weight is about 128.8 grams;theoretical for methylcyclohexyl diamine is about 128.3 grams. Aninfrared spectrum of the distilled material shows no contamination witharomatic. Yield of distilled diamine, basis toluene diamine charge, isabout 78.2 percent.

b) About 15 parts of reduced 80 percent 2,4- and 20 percent 2,6-toluenediamine prepared in Example 8(a) is dissolved in about 250 parts of dryorthene and this solution treated with CO at about 25 C. There results acolloidal dispersion of the CO -salt of the diamines in orthene. Thisdispersion is then added, at 5 C., to a stirred solution containingabout 100 parts of dry orthene which has been saturated with phosgene atabout 05 C. A fine slurry results. This is then heated according to thefollowing schedule with vigorous stirring and a constant stream ofphosgene being passed through the slurry: 1 hour at 75 C., 2 hours at100 C., 6 hours at 125 C., 6 /2 hours at 142 C.

At this point the reaction mixture is a dark, clear solution whichcontains considerable NCO as shown by infrared analysis. The solution isthen flushed free of phosgene with nitrogen and fractionally distilled.The product is obtained at about 128-129" C. at 12 mm. pressure. About a36 percent yield of 80 percent 2,4- and 20 percent 2,6-methylcyclohexane diisocyanate is obtained.

(c) About 64 parts 'by weight of reduced 80 percent 2,4- :and 20 percent2,6-toluene diamine prepared as in Example 8(a) are dissolved in about485 parts of dry orthene. This solution is treated with CO at about 90C. for about 6 /2 hours. A colloidal suspension of the CO salt inorthene resulted. This suspension is then treated with phosgene andvigorous stirring for about 4 hours at about 05' C. The temperature isthen increased and the slurry is treated with phosgene at about 100 C.for several hours, at about 110 C. for several hours and at about 160 C.for a total of about 28 hours. The reaction mixture is finally treatedat about 174177 C. for about 9 hours. During the course of the aboveheating program an insoluble solid forms in the reaction mixture anddoes not appear to react further with additional heating. (Furtherinvestigation indicates that this solid may be an N,N-disubstituted ureaarising from the condensation of about 1 mol of phosgene and about 2mols of reduced toluene diamine. It forms if the temperature is raisedtoo rapidly during the hot phosgenation step.) The above mixture of adark, clear liquid plus the solid is then flushed free of phosgene andfiltered. The filtrate is fractionally distilled under vacuum and theproduct obtained at about 126 C./12 mm. Analysis of this cut shows anNCO content of about 42 percent (about 46 percent theoretical). Infraredanalysis reveals no aromatic material, no free amine and much -NCO.About a 16.5 percent yield of 80 percent 2,4- and 20 percent 2,6-methylcyclohexane diisocyanate is obtained.

(d) About 30 parts of reduced 80 percent 2,4- and 20 percent 2,6-toluenediamine prepared as in Example 8(a) are dissolved in about 200 parts ofdry orthene and this solution is added to a solution consisting of about400 parts of dry orthene saturated with phosgene at about 05 C. Thecombining of these solutions is carried out at 0-5 C. with vigorousstirring and a continuous stream of phosgene passing through thereaction mixture. The resulting slurry is then treated as follows: withstirring and continuous phosgene, heated at 05 C. for about 15 minutes,at C. for 5 /2 hours, at C. for 4 hours, at C. for 4 hours and at 140 C.for 3 hours. At this point the reaction medium is a brown, clearsolution. This solution is fractionally distilled and the productobtained at 127 C./12 mm., 21.2 percent yield of 80 percent 2,4- and 20percent 2,6-methyl cyclohexane diisocyanate is obtained. Infraredanaly'is show no aromaticity, no free amine and much NCO.

It is to be understood that the foregoing working examples are given forthe purpose of illustration and that any other suitable hydrogenationcatalyst, amine, active hydrogen containing compound, urethane catalystor the like could be used provided that the teachings of this disclosureare followed.

The cyclohexane polyamines and cyclohexane polyisocyanates of theinvention are useful to prepare polyurethane plastics as disclosedabove.

Although the invention has been described in considerable detail in theforegoing, it is to be understood that such detail is solely for thepurpose of illustration and that many variations can be made by thoseskilled in the art without departing from the spirit and scope of theinvention except as set forth in the claims.

What is claimed is:

1. Cyclohexylene diamines having the formula:

CH R

CH CH CH CH wherein R is lower alkyl and there are at least two isomerspresent.

2. Mixtures of 2,4- and 2,6-lower alkyl Cyclohexylene diamines.

3. A mixture of at least 50 percent 2,4-lower alkyl cyclohexylenediamine and at least 5 percent 2,6-lower alkyl cyclohexylene diamine.

4. A mixture of at least 50 percent 2,4-hexahydrotoluene diamine and atleast 5 percent 2,6-hexahydrotoluene diamine.

5. A mixture of about 65 percent 2,4-hexahydrotoluene diamine and about35 percent 2,6-hexahydrotoluene diamine.

6. A mixture of about 80 percent 2,4-hexahydrotoluene diamine and about20 percent 2,6-hexahydrotoluene diamine.

References Cited UNITED STATES PATENTS 2,828,313 3/1958 Scholz et a1260513 X CHARLES B. PARKER, Primary Examiner.

P. C. IVES, Assistant Examiner.

US. Cl. X.R.

